as a guide.. I was a 34D pre op, i had an uplift and implants which have taken me to what it think is an e/f but can’t tell with all the strapping, it wasn’t important if you get a Macom. a 34 rib measurement is a medium in Macom bra catalogue no. 1007, the cups are one fits all so they mould to your new cup size so i was told to buy the correct one to fit my pre op rib measurement and the cups will sort themselves out xxx